for i in list:
j = i + 1
print i - j
This will print out -1 times the length of list
What I wanted to do is to print the difference between value i and the next in the list.
Am I clear?
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3 Answers
for i in list:
binds i to the elements of list, not its indexes. You might have meant
for i in xrange(len(list)):
or
for i, _ in enumerate(list):
Then get the element at index i with list[i].
(And please don't call a list list; that's the name of a Python built-in function.)
Comments
Unlike JavaScript, iterating over a sequence in Python yields elements, not indexes.
for i, j in zip(L, L[1:]):
print j - i
answered Jan 15, 2012 at 0:28
Ignacio Vazquez-Abrams
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Comments
Try this:
lst = [1, 2, 3, 4]
for i in xrange(1, len(lst)):
print lst[i-1] - lst[i]
Notice that in the line for i in list, i is an element of list, not an index. In the above code, i is indeed an index. Also, it's a bad idea calling a variable list (Python uses that name for something else). I renamed it to lst.
1 Comment
AWE
for i in xrange(1, len(lst)): print lst[i-1] - lst[i] That is exactly how I used larsmans answer.
